Flame-resistant polycarbonate ABS moulding materials

Abstract

The present invention relates to thermoplastic polycarbonate molding compositions which contain phosphazenes and special graft polymers produced by means of redox initiator systems and are distinguished by substantially improved mechanical properties.

What is claimed is:  
     
       1. A thermoplastic moulding composition consisting of: 
       A) 40 to 99 parts by weight of at least one of aromatic polycarbonate and polyester carbonate;  
       B) 0.5 to 60 parts by weight of a graft polymer prepared from,  
       B.1) 5 to 95 wt. % of one or more vinyl monomers, and  
       B.2) 95 to 5 wt. % of one or more particulate diene rubbers having a glass transition temperature of <10° C., which are produced by emulsion polymerisation,  
       said graft polymer being prepared by means of a graft polymerisation in the presence of an initiator system comprising an organic hydroperoxide and ascorbic acid, said graft polymerisation having a grafting yield of >60 wt. %; 
       C) 0 to 45 parts by weight of at least one thermoplastic polymer selected from the group consisting of thermoplastic vinyl (co)polymers and polyalkylene terephthalates;  
       D) 0.1 to 50 parts by weight of at least one component selected from the group consisting of phosphazenes represented by the following formulae,                    
        in which  
       R is in each case identical or different and denotes amino, C 1  to C 8  alkyl, in each case optionally halogenated, or C 1  to C 8  alkoxy, C 5  to C 6  cycloalkyl, C 6  to C 20  aryl, C 6  to C 20  aryloxy, or C 7  to C 12  aralkyl, in each case optionally substituted by alkyl and/or halogen,  
       k denotes 0 or a number from 1 to 15;  
       E) 0 to 5 parts by weight of fluorinated polyolefin; and  
       F) optionally at least one additive selected from the group consisting of lubricants, mould release agents, nucleating agents, anti-static agents, stabilisers, dyes and pigments.  
     
     
       2. The moulding composition of  claim 1  comprising: 
       60 to 98.5 parts by weights of A;  
       1 to 40 parts by weight of B;  
       0 to 30 parts by weight of C;  
       2 to 35 parts by weight of D; and  
       0.1 to 1 parts by weight of E.  
     
     
       3. The moulding composition of  claim 1  comprising 2 to 25 parts by weight of C. 
     
     
       4. The moulding composition of  claim 1  comprising 5 to 25 parts by weight of D. 
     
     
       5. The moulding composition of  claim 1  wherein vinyl monomers B.1 are mixtures prepared from: 
       B.1.1 50 to 99 parts by weight of at least one member selected from the group consisting of vinyl aromatics, ring-substituted vinyl aromatics and methacrylic acid (C 1 -C 8 )-alkyl esters; and  
       B.1.2 1 to 50 parts by weight of at least one member selected from the group consisting of vinyl cyanides, (meth)acryllc acid (C 1 -C 8 alkyl esters, anhydrides of unsaturated carboxylic acids and imides of unsaturated carboxylic acids.  
     
     
       6. The moulding composition of  claim 1  wherein the grafting yield, of said graft polymerisation, is >75 wt. %. 
     
     
       7. The moulding composition of  claim 1  wherein the grafting yield, of said graft polymerisation, is >85 wt. %. 
     
     
       8. The moulding composition of  claim 1  wherein component D is selected from the group consisting of propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene, aminophosphazene and fluoroalkylphosphazenes. 
     
     
       9. A method of producing the moulding composition of  claim 1  comprising mixing and melt-compounding components A to E and optionally component F. 
     
     
       10. The molding composition of  claim 1  wherein diene rubber B.2) is at least one member selected from the group consisting of diene rubber copolymers of diene rubber. 
     
     
       11. The molding composition of  claim 1  wherein dien rubber B.2) is polybutadiene rubber. 
     
     
       12. The molding composition of  claim 1  wherein the hydroperoxide, of the graft polymerisation of said graft polymer B, is at least one member selected from the group consisting of cumene hydroperoxide, tert.-butyl hydroperoxide and hydrogen peroxide. 
     
     
       13. A molded article comprising the composition of  claim 1 .